ABSTRACT

It is hard to imagine a greater challenge to a permanent osseous implant than to put it in an environment where one end of the implant is exposed to high concentrations of debris and bacteria while the opposite end maintains direct metal to bone contact without hydroxyapatite or a porous coating, and the entire implant is subjected to very high loads. Yet, this is done routinely by dentists using the so-called Bra˚nemark concept (1). Such implants that have survived their first postoperative year have a 10-year survival comparable to the best total joint prostheses. How is this possible? When implanting a Bra˚nemark implant, the use of an atraumatic operative technique is considered extremely important. Further, after the implant is in place, the mucosa is sutured and the implant allowed to osseointegrate under unloaded conditions before the outer end of the implant is exposed and attached to a load-bearing device. Immediate load bearing using this kind of implant in cancellous regions almost inevitably leads to failure. The superior result with unloaded osseointegration emphasizes the importance of the early postoperative period for the longevity of the implant. Some early biological processes have to proceed under unloaded conditions for these implants to be successful.